You may notice that Eclipse shows a lot of errors. Don't worry at this point it is perfectly normal. Some of these errors may be validation errors, while the others come to be because Eclipse can't find the needed .jar libraries.
Validation is often too strict on HTML pages, and can therefore be a real nuissance, slowing down Eclipse horribly. It can be turned of in Eclipse preferences:
In Eclipse: Window -> Preferences -> Validation
Also make sure that your java compiler level is 5.0:
In Eclipse: Window -> Preferences -> Java -> Compiler
Now the real problem was that Eclipse can't locate the Maven repository. While running the Maven install plugin, it automatically downloads the necessary jars, and stores them in a repository under the system user's home directory. Now Eclipse needs to know where that is. To do this, we need to define a "classpath variable":